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1.
J Dairy Sci ; 100(9): 7522-7533, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28647336

RESUMEN

Mammary gland quarters have usually been considered to be anatomically and physiologically independent, but some recent research has indicated more interdependence than previously reported. The objective of this study was to compare milk composition (fat, total protein, lactose, solids-not-fat, and chloride) and health status (somatic cell count, differential leukocyte count, and lactate dehydrogenase) of milk samples from unaffected mammary glands of an udder with a single clinically inflamed quarter to results of milk samples from healthy mammary glands of healthy cows. The study was designed as a prospective case control study with case and control cows matched by parity and days in milk. Cases were defined as cows (n = 59) experiencing clinical mastitis in a single mammary gland, and controls (n = 59) were defined as cows that had not experienced clinical mastitis during the current lactation. Quarter milk samples were collected from all mammary glands adjacent to clinically affected quarters of cases and from the same mammary glands of controls. Samples were used to assess concentration of chloride and lactate dehydrogenase, fat, total protein, solids-not-fat, somatic cell count, and differential leukocyte count. Microbiological analysis was also performed on milk samples obtained from clinically affected mammary glands (n = 59). Logistic regression models were used to assess possible associations among quarter somatic cell count (≥150,000 cells/mL) and quarter type (adjacent to case or control). Multivariate linear models were used to compare milk composition and health status between quarter types. A total of 170 quarters were enrolled per group. Milk obtained from adjacent quarters of cases contained a lesser concentration of total protein, lactose, and solids-not-fat, but had a greater concentration of fat and chloride. The somatic cell count, total leukocyte count, and absolute numbers of neutrophils, lymphocytes, and macrophages were all increased in milk obtained from adjacent quarters of case cows compared with milk obtained from quarters of control cows. The relative proportion of neutrophils was increased, whereas the proportion of macrophages was decreased in milk obtained from cases. Approximately 30% of milk samples obtained from adjacent quarters of cases had a somatic cell count ≥150,000 cells/mL compared with 12% of milk samples obtained from quarters of control cows. The position of the mammary gland was not associated with any outcomes. In conclusion, our results support previous research that indicates the immune response to intramammary infection in a single mammary gland quarter alters milk composition and health status throughout the udder.


Asunto(s)
Estado de Salud , Glándulas Mamarias Animales , Mastitis Bovina , Leche/química , Animales , Estudios de Casos y Controles , Bovinos , Recuento de Células , Femenino , L-Lactato Deshidrogenasa/análisis , Glándulas Mamarias Animales/inmunología , Glándulas Mamarias Animales/microbiología , Mastitis Bovina/inmunología , Mastitis Bovina/microbiología , Leche/microbiología , Paridad , Embarazo , Estudios Prospectivos
2.
J Dairy Sci ; 99(10): 7886-7897, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27497904

RESUMEN

The Serra da Canastra region, located in southwestern Minas Gerais, Brazil, is recognized worldwide for its tradition of producing artisanal cheeses. However, as production is done by hand, great variability exists in the characteristics of artisanal Minas cheese. Thus, it is important to characterize the sensory profile of these products and verify the quality attributes that lead to their acceptance. Therefore, this study aimed to characterize the dynamic sensorial profile of artisanal Minas cheese produced in the Serra da Canastra region through temporal dominance of sensations and sensory acceptance tests and verify the attributes that lead to product quality. We observed that the texture and flavor profile varied among the evaluated artisanal Minas cheeses from Serra da Canastra, some cheeses being more characterized by creamy and soft or hard and firm sensations, whereas others had high dominance rates for crumbly texture. In relation to flavor, salty and bitter tastes were dominant in most cheeses, some also being characterized by a sour taste, and others by buttery and rancid attributes, which indicates a lack of product standardization. However, all samples obtained scores between 6 (liked slightly) and 7 (liked moderately), indicating good acceptability in relation to the texture and flavor of the evaluated cheeses. Moreover, it is possible to infer that creamy and soft or hard and firm are positive attributes for cheese texture, and bitter, buttery, salty, and acid taste drive cheese acceptance. This study provides important information for product standardization, quality improvement, and process origin indications, besides providing quality attributes that meet consumer desires.


Asunto(s)
Queso , Gusto , Animales , Brasil , Sensación , Percepción del Gusto
3.
Insect Biochem Mol Biol ; 36(7): 561-9, 2006 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-16835021

RESUMEN

The digestive system of Ceratitis capitata was characterized during its larval development and in the insect stage. Disaccharidases against maltose and sucrose were more evident in the 2nd and 3rd day of larval development and in the adult stage, respectively. Glycosil-hydrolyses with higher specific alpha-galactosidasic and beta-galactosidasic activities were detected in the 2nd and 3rd day of the larval stage, respectively. Specific proteolytic activities against azocasein showed an increase in the 4th and 5th day of the larval stage and in the adult stage. Specific hemoglobin activities were constant between 2nd and 6th day of the larval stage. The larvae used mainly serine proteinases, such as trypsin/chymotrypsin, and the adult insects only chymotrypsin-like enzymes in their digestive process. Two serine proteinases were separated from zymogram between the 4th and 5th day of larval development and in the adult stage. Effect of soybean trypsin inhibitor (SBTI, a serine proteinase inhibitor) on development of C. capitata was examined by bioassay. C. capitata was susceptible to SBTI which affected larval mass at ED50 3.01%.


Asunto(s)
Dípteros/enzimología , Serina Endopeptidasas/metabolismo , Inhibidor de la Tripsina de Soja de Kunitz/farmacología , Animales , Caseínas/farmacología , Dípteros/crecimiento & desarrollo , Electroforesis en Gel de Poliacrilamida , Glicósido Hidrolasas/metabolismo
4.
Protein Expr Purif ; 58(1): 61-9, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18171621

RESUMEN

beta-N-Acetylhexosaminidases (EC 3.2.1.52) belong to an enzyme family that hydrolyzes terminal beta-d-N-glucosamine and beta-d-N-galactosamine residues from oligosaccharides. In this report, we purified a novel beta-N-acetylhexosaminidase (Pcb-NAHA1) from the marine zoanthid Palythoa caribaeorum by applying ammonium sulfate fractionation, affinity chromatography on a chitin column, followed by two rounds of size exclusion chromatography. SDS-PAGE analysis indicated a single band protein of apparent homogeneity with a molecular mass of 25kDa. The purified enzyme preferentially hydrolyzed p-nitrophenyl-2-acetoamide-2-deoxyamide-2-deoxy-beta-d-N-acetylglucosamide (pNP-GlcNAc) and to a lesser extent p-nitrophenyl-2-acetoamide-2-deoxyamide-2-deoxy-beta-d-N-acetylgalactosamide (pNP-GalNAc). Detailed kinetic analysis using pNP-GlcNAc resulted in a specific activity of 57.9 U/mg, a K(m) value of 0.53 mM and a V(max) value of 88.1 micromol/h/mg and k(cat) value of 0.61s(-1). Furthermore, purified Pcb-NAHA1 enzyme activity was decreased by Hg Cl(2) or maltose and stimulated in the presence of Na(2)SeO(4,) BaCl(2), MgCl(2,) chondroitin 6-sulfate, and phenylmethylsulfonylfluoride. The optimum activity of Pcb-NAHA1 was observed at pH 5.0 and elevated temperatures (45-60 degrees C). Direct sequencing of proteolytic fragments generated from Pcb-NAHA1 revealed remarkable similarities to plant chitinases, which belong to family 18, although no chitinase activity was detected with Pcb-NAHA1. We conclude that beta-N-acetylhexosaminidases, representing a type of exochitinolytic activity, and endo-chitinases share common functional domains and/or may have evolved from a common ancestor.


Asunto(s)
Antozoos/enzimología , beta-N-Acetilhexosaminidasas/aislamiento & purificación , beta-N-Acetilhexosaminidasas/metabolismo , Secuencia de Aminoácidos , Animales , Antozoos/metabolismo , Cinética , Datos de Secuencia Molecular , Alineación de Secuencia , Especificidad por Sustrato , beta-N-Acetilhexosaminidasas/química
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